Re: [PATCH] Btrfs: skip commit transaction if we don't have enough pinned bytes

[Nikolay Borisov <nborisov@suse.com>]

On 19.05.2017 20:39, Liu Bo wrote:
> We commit transaction in order to reclaim space from pinned bytes because
> it could process delayed refs, and in may_commit_transaction(), we check
> first if pinned bytes are enough for the required space, we then check if
> that plus bytes reserved for delayed insert are enough for the required
> space.
> 
> This changes the code to the above logic.
> 
> Signed-off-by: Liu Bo <bo.li.liu@oracle.com>

Please add:
Fixes: b150a4f10d87 ("Btrfs: use a percpu to keep track of possibly
pinned bytes")

> ---
>  fs/btrfs/extent-tree.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index e390451c72e6..bded1ddd1bb6 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4837,7 +4837,7 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info,
>  
>  	spin_lock(&delayed_rsv->lock);
>  	if (percpu_counter_compare(&space_info->total_bytes_pinned,
> -				   bytes - delayed_rsv->size) >= 0) {
> +				   bytes - delayed_rsv->size) < 0) {
>  		spin_unlock(&delayed_rsv->lock);
>  		return -ENOSPC;
>  	}
> 

With the minor nit above:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>